The present invention relates to a squeeze actuated wrench and more specifically to a compact squeeze actuated ratchet wrench with a lever arrangement having a high mechanical advantage for the transfer of forces between the handle and the rotatable socket.
Numerous attempts have been made to develop a compact ratchet wrench with a high degree of mechanical advantage. Such attempts are exemplified by the Lachance U.S. Pat. No. 3,447,404, the Gregory U.S. Pat. No. 3,616,714 and the Williams U.S. Pat. No. 3,726,161. While both Gregory and Williams disclose a squeeze actuated ratchet wrench, the lever design is such as to cause inefficiency with a resultant decrease in mechanical advantage. For example, both Gregory and Williams utilize a sliding cam action for effecting rotation of the socket. The mechanical losses associated with a sliding cam action due to the friction losses at the cam surface are such as to decrease the efficiency of the wrench. Moreover, wrenches such as disclosed in Lachance, which are not squeeze actuated, are not as versatile or maneuverable as desired.
Another area of inefficiency exhibited in the prior art is the location of the driver member relative to the outer periphery of the socket. It should be appreciated that the torque transmitted from the driver to effect rotation of the socket is dependent upon the force transmitted by the driver and the angle at which the driver engages with the toothed outer periphery of the socket. For maximum efficiency the driver should be disposed 90.degree. from a radius of the socket and the closer to 90.degree., the higher the mechanical efficiency. Since the prior art does not closely approach a 90.degree. angle between the driver and the socket, the efficiency of the prior art devices is not maximized. It should be appreciated that the teeth of the driver means of the prior art such as is exemplified by Williams, Gregory or Lachance engage a plurality of the teeth on the outer periphery of the socket means. Obviously, by engaging a plurality of teeth, the force is spread out around the perimeter of the socket means and does not closely approach the 90.degree. optimum angle.